Embodiments of the present invention relate to medical systems that can deliver therapies involving the use on an extracorporeal circuit or the use as an implant including but not limited to hemodialysis, hemodiafiltration, ultrafiltration, plasmapheresis, fluid exchange, gas exchange, drug delivery, and treatment of diseases or infections or combination of the above therapy modalities. These embodiments also pertain to the treatment of hypervolemia in patients with Congestive Heart Failure (CHF) and other organ failure, and to making portable and wearable devices that can treat a patient for long periods of times.
Traditionally in hollow fiber hemodialyzers, hemofilters, and hemodiafilters, the blood flows through the lumen of the fiber. These devices are susceptible to fiber clogging resulting from thrombus formation which results in unacceptable increase in circuit pressure and results in the termination of treatment.
A key requirement to enable a longer, more efficient and more cost-effective therapies is the ability to deliver long-term blood processing on a continuous basis without premature filter clogging. Thrombus formation and clogging necessitates frequent filter changes during treatment and is associated with negative consequences such as blood loss and life threatening infections. In the absence of long filter life, the use of ultrafiltration, dialysis or serum replacement devices is limited to treatment in the hospital setting. Numerous investigations by various groups have established that thrombosis causes fiber-clogging leading to an unacceptable growth in filter pressure drop and leading to short filter life not exceeding about 20 hours. The average filter life of intra-luminal conventional hemofiltration/ultrafiltration during Continuous Renal Replacement Therapy (CRRT) or ultrafiltration is typically less than 25 hours of operating time. With complex anticoagulation regimens using regional citrate anticoagulation (RCA) this time may be extended to 35 to 40 hours. Because of these filter life limitations and the complexity of the anticoagulant regimen, patients must be treated in a healthcare facility under supervision of trained medical professionals, which is costly to the healthcare system. The significant increase in cost and expenses is unacceptable in view of the already high cost incurred in treating the CHF, organ failure, sepsis and End Stage Renal Disease (ESRD) population in the United States.
In order to address these needs, it would be helpful to develop hemodialysis, hemodiafiltration, hemofiltration, CRRT and ultrafiltration methods and filters that can achieve long-term treatment without such frequent filter replacement. This would help to reduce the associated product and personnel costs. Thrombus formation during long duration ultrafiltration or other related treatment modalities needs to be minimized to allow safe hemofiltration or ultrafiltration for at least 72 hours without filter clogging. With the current state of technology, this is not possible. Achieving a reduction of thrombus formation or filter clogging would make it possible to develop new medical devices and treatment modalities for long-term therapy with minimal need for filter replacement. All therapies requiring the use of an extracorporeal circuit or an implant will equally benefit from such new methods and filters that can minimize filter clogging and that can provide better filter performance. Hence, there is a need for improvements in hemofiltration, hemodialysis, hemodiafiltration and other related blood processing therapies and methods that can minimize filter clogging.